I found this app during a stretch when I couldn't sleep and didn't want to scroll through social media https://1000apk.ru/71-pesochnica.html . It turned out to be exactly what I needed. There's no story, no objectives, no scores — just a black canvas and a palette of materials. You tap to pour sand, water, oil, mercury, fire, or cosmic dust, and then you watch.
The interesting part is that these materials don't just sit there. They follow simple physics rules. Sand piles up and slides. Water flows downhill. Oil floats on top of water. Fire spreads along anything flammable. There are dozens of substances, and you can combine them in ways the app doesn't spell out for you. Some of the reactions genuinely surprise you the first time you see them.
There are recipes worth experimenting with. Pour cement, then water on top — it hardens and darkens over time. Drop a lightning bolt, then neon gas — you get a glowing effect. Plant seeds and water them, and after a couple of minutes, flowers start to grow. A more playful one: pour lava, then water, and the steam becomes rain falling across the whole screen. The same trick works with gasoline or oil, just with a different look.
Some materials are locked behind the paid version, like neon gas and lightning. But the free set is big enough that you can spend a lot of time just messing around. What I like most is that nothing here demands anything from you. You don't have to win, you don't have to progress, you don't have to be good at it. You just play with substances and see what happens. It sounds simple, and it is — but that's the whole point. It quiets your head better than most things I've tried.